Various types of motor lead mounts are known in the art. The motor leads are those wires that come from the motor and are routed to, for example, a power source or a control system. In a particular configuration in which a motor is connected to equipment, such as a pump, that may subject the motor to vibration or movement, the wire leads can easily be subjected to stresses that can break or yield the wire.
One accepted method to alleviate the problems of overstressing the wire leads is to use braided cable rather than solid conductors. Because the braided cable is composed of many strands of relatively thin gauge wire, it has been shown to better withstand the constant flexing that can result from vibration and movement. In a typical motor design, three leads are connected to the motor, namely, a first, common stranded lead, a second, solid conductor start wire and a third, also solid conductor main wire. Typically, the start and main wires are insulated wires that have 1-2 mils of enamel insulation. The enamel insulation is of a non-shrink type.
In one known method of mounting such leads that is used in vibration-free or substantially vitration-free environments, the leads exit the motor in a vertical direction, generally downwardly. The leads are then bent to run in a horizontal direction, which can be routed to, for example, a cable tray or conduit. The three leads, namely, the common, start and main leads, are bundled together and are pulled downward from the motor. When the leads are bent from the vertical to the horizontal direction, the common stranded lead is positioned on the outside of the bend. That is, the common lead is the outermost wire, and the wires are bundled so that the maximum amount of flexing that the bundled wires will be subjected to (at the outside of the bend) will be seen by the braided common lead. This, in turn, results in the start and main wires, which are positioned within the bend of the common lead, being subjected to less flexing. This arrangement, however, is used, as stated above, in vibration-free or substantially vibration-free environments.
In addition, in known mounting configurations, the bundled wires are typically tied or fastened to one another immediately downstream of a relatively short radius bend in the wires. That is, a wire tie is generally positioned immediately adjacent to or abutting the wire bend at the vertical portion of the wire run.
There are a number of difficulties that have been observed with current wire lead tie configurations. First, because the magnet wire leads can be part of the stator winding leads, stresses in these wire must be kept to a minimum. As a result, the magnet wire arrangement was not used in connection with motors subjected to movement and vibration because of the potential for the wire to yield or break. Second, the braided cables can be considerably more expensive than solid conductor wires. As such, use of multiple braided cables could increase the cost for motor mounting. Thus, cost considerations often played a large part in mounting configurations.
Accordingly, there continues to be a need for a magnet wire lead tie method which permits the use of solid conductor wires and which increases the reliability of the leads running from the motor to the associated source or control system. Such a method permits the use of stator winding solid conductor leads in a motor mounting configuration in which the motor can be subjected to vibration and movement.